Computer Models to Investors: Short Everything

Investors have started to shake off last year’s steep losses, helping markets regain some ground in 2019. But the robots are still almost uniformly bearish.

Trend-following investment strategies — a computer-based way of trading that has become a major force in some markets — have gone from bullish to bearish to a degree not seen in a decade, according to an analysis of algorithms that buy or sell based on asset-price momentum.